1. Field of the Invention
The present invention relates to a coating applicator and method for applying coating material in stripes on one side or both sides of a base continuously running.
2. Related Art of the Invention
As for a coating applicator for applying coating fluid on the surface of a base running continuously, an extrusion type coating applicator is known, which comprises a manifold for spreading coating fluid in the direction of the coating width and a slit for commutating and discharging coating fluid supplied to the manifold.
As for a method for applying the coating film in stripes by the extrusion type coating applicator, there is a method for discharging the coating fluid while splitting the flow of it within a slit by providing (a) partition(s) in the slit.
In addition, the method using the partition(s) adapts the following method for uniforming the film thickness in the direction of coating width. Namely, in a T-shape die for extruding a resin film or sheet, a lip edge of a nozzle is transformed by pushing or pulling a differential screw or a heat bolt or by pushing into with an air pressure drive or the like, so that the discharge amount is finely adjusted to uniform the film thickness in the direction of the width. Or the nozzle is partially heated by a heater provided within the nozzle, which changes the flow property of the resin to be applied by changing the temperature of it so that the film is uniformed in thickness in the direction of the width.
Moreover, in the Japanese publication of unexamined patent application H9(""97)-271705, a method is disclosed in a coating applicator forming a coating film of photo-resister fluid or the like on a semiconductor wafer or a glass substrate, wherein the lip edge of a nozzle is transformed by a piezo-actuator to finely adjust the discharge amount so that the film thickness is uniformed in the direction of the coating width of the coating film.
In case of the coating application in stripes, it is important to uniform the discharge amount in the direction of the coating width at the slit outlets for each of the stripes of coating fluid in order to uniform the coating amount in the direction of the coating width for each stripe.
In the above mentioned T-shape die or other coating applicators, however, in case of applying over the entire width, it is easy to uniform the discharge amount in the direction of the coating width by transforming the lip edge of the nozzle as well as by adjusting transformation of the peripheral part of that portion at the same time. In case of the coating application in stripes, however, because it is important for the film thickness of the coating for each stripe to be uniformed, it is necessary to uniform the discharge amount for each stripe. If the periphery of the portion transformed at the lip edge of the nozzle is also transformed, however, it is not easy to control the inconsistency of the film thickness of the coating for each stripe.
It is the purpose of the present invention to solve the above mentioned problem of the coating applicator according to the prior art, and to provide a stripe coating applicator and method for uniforming the film thickness in the direction of the coating width of the coating fluid even in case of the stripe application.
According to the first aspect of the present invention (corresponding to Claim 1), the applicator for coating at least two stripes comprises;
a plurality of slit outlets provided at a nozzle edge;
an upper and a lower pair of block edges forming said slit outlets;
stripe partitions partitioning a plurality of said slit outlets;
notches formed on at least either one of said block edges toward the direction of coating fluid being discharged, said formation of said notches being corresponding to positions of said stripe partitions;
movable parts formed by said notches and thin parts at said block edge(s) where said notches are provided; and
slit gap adjustment means for adjusting slit gaps by moving said movable parts.
Also, according to the second aspect of the present invention (corresponding to Claim 9), the applicator for applying at least two stripes, comprises a nozzle having slit gap adjustment means for adjusting slit gaps by moving movable parts formed at either edge of an upper and lower pair of blocks forming slit outlets, by thin parts, wherein;
displacement sensors measure displacement of said movable parts; and
said slit gap adjustment means performs a feedback control based on numeric values outputted from said displacement sensors.
Furthermore, according to the third aspect of the present invention (corresponding to Claim 12), a slit gap adjustment method for adjusting a slit gap in a stripe coating applicator according to the applicator of the present invention , is such that
a relationship between an adjustment amount for coating film and a movement of said movable part is prepared in advance;
a thickness of the coating film after application is detected;
a thickness adjustment amount is calculated from the thickness and, based on said relationship, an amount of said movement of the movable part is calculated; and
based on the movement of the movable part, said movable part is moved by said slit gap adjustment means.